Cardiac Resynchronization Therapy

Cardiac resynchronization therapy (CRT) is a treatment for heart failure, which is caused by a weakened heart muscle. The condition causes shortness of breath, fatigue during physical activity and fluid retention.

About one-third of people with heart failure have weak or irregular heartbeats because the heart’s electrical signals are slower than normal. CRT uses an implanted device to improve heart rate. It improves heart failure symptoms in 70 to 80 percent of patients.

The type of device may be a biventricular pacemaker (CRT-P) or a biventricular implantable cardioverter defibrillator (CRT-D). Unlike other pacemakers that have one or two wires, a biventricular pacemaker has three wires. One wire goes to each ventricle, while a third connects to the right atrium (one of the heart’s upper chambers). The wires monitor each chamber’s activity to deliver well-timed impulses to help the heart chambers work together.

Who Is It for?

Your cardiologist may recommend CRT if:

What to Expect Before, During and After the Procedure

Before the procedure

You’ll receive an IV with fluids, antibiotics and light sedation to help you relax or fall asleep. Local anesthesia is applied to numb the skin where the CRT device will be implanted.

During the procedure

Your doctor inserts the biventricular pacemaker’s three wires through an IV and guides them to your heart. After the CRT device is connected to the wires, the doctor inserts the device into a pocket under the skin through an incision.

After the procedure

Most patients spend the night in the hospital after getting a CRT device. Arrange to have someone drive you home from the hospital.

Most people can resume their usual daily activities after a few days. Your care team will provide you with specific instructions on what movements and activities to limit or avoid in the days and weeks following your surgery. As with any cardiac device implantation, you should avoid or limit strenuous activity with the arm on the affected side, including raising the arm over the head and heavy lifting, for four to six weeks following implantation.

Benefits of Cardiac Resynchronization Therapy

Benefits of CRT include:

• Assists your heart in pumping more blood to your body.
• Makes your heart work more efficiently.
• Relieves shortness of breath and other common heart failure symptoms.
• Prevents abnormal heart rhythms.
• Relieves mitral regurgitation (when blood flows backwards into your heart’s mitral valve).
• Improves your ability to exercise.
• Increases your life expectancy.

Note that not all heart failure is due to a slowdown of electrical conduction. Also, even when CRT restores the heart’s electrical synchronization, the heart muscle may remain weak.

Risks of Cardiac Resynchronization Therapy Implantation

Risks related to CRT (biventricular pacemaker or ICD) implant may include:

• Bleeding.
• Infection.
• Pneumothorax, more commonly known as collapsed lung, is when air leaks into the space between the lung and chest wall.
• Cardiac perforation (a tear or rupture in the heart chamber wall) or cardiac tamponade (pressure on the heart caused by excess blood and fluid in the sac surrounding it).
• Failure of the device.
• Lead dislodgment requiring another procedure to relocate or replace the lead.

Follow-Up Care

Your physician will check your pacemaker several times a year, in the office and remotely if your pacemaker has a remote monitor.

Your pacemaker battery will last for five to nine years. About three months before the battery runs down, you will be scheduled for device replacement. Surgery is required to replace the battery, which is a simpler procedure with a shorter recovery period than implantation surgery.